Evaluation of neutron cross sections of^(48)Ti based on the Unified-Monte-Carlo-B method  

作　　者：夏候琼 续瑞瑞 刘萍 Roberto Capote 田源 陶曦 吴小飞 张玥 葛智刚 舒能川 冯松 Hou-Qiong Xia;Rui-Rui Xu;Ping Liu;Roberto Capote;Yuan Tian;Xi Tao;Xiao-Fei Wu;Yue Zhang;Zhi-Gang Ge;Neng-Chuan Shu;Song Feng(China Nuclear Data Center,China Institute of Atomic Energy,Beijing 102413,China;NAPC-Nuclear Data Section,P.O.Box 100,Vienna International Centre,A-1400,Vienna,Austria;School of Nuclear Science and Technology,University of South China,Hengyang 421001,China)

机构地区：[1]China Nuclear Data Center,China Institute of Atomic Energy,Beijing 102413,China [2]NAPC–Nuclear Data Section,P.O.Box 100,Vienna International Centre,A-1400,Vienna,Austria [3]School of Nuclear Science and Technology,University of South China,Hengyang 421001,China

出　　处：《Chinese Physics C》2024年第7期118-130,共13页中国物理C（英文版）

基　　金：Supported by the National Key Research and Development(R&D)Program(2022YFA1602403);Continuous Support Basic Scientific Research Project BJ010261223282。

摘　　要：A cross section evaluation of neutron induced reactions on^(48)Ti is undertaken using the Unified Monte Carlo-B(UMC-B)approach.The evaluation concentrates on estimating the covariance and the use of the UMC-B allows avoiding the deficiencies of linear regression brought by the traditional least squares method.Eight main neutron and charged particle emission reactions from n+^(48)Ti in the fast neutron energy region below 20 MeV are studied in this work.The posterior probability density function(PDF)of each neutron cross section is obtained in a UMC-B Bayesian approach by convoluting the model PDFs sampled based on model parameters and the likelihood functions for the experimental data.Nineteen model parameters including level density,pair corrections,optical model and Kalbach matrix element parameter are stochastically sampled with the assumption of normal distributions to estimate the model uncertainty.The Cholesky factorization approach is applied to consider potential parameter correlations.Finally,the posterior covariance matrices are generated using the UMC-B generated weights.The new evaluated results are compared with the CENDL-3.2,ENDF/B-VIII.0,JEFF-3.3,TENDL-2021 and JENDL-5 evaluations and differences are discussed.

关 键 词：COVARIANCE Unified Monte Carlo B(UMC-B) ^(48)Ti neutron cross sections Cholesky factor-ization approach 

分 类 号：TL329.2[核科学技术—核技术及应用]